Mask



FIG. 1 is a top front perspective view of a mask showing our new design;

FIG. 2 is a front view of FIG. 1 ;

FIG. 3 is a rear view of FIG. 1 ;

FIG. 4 is a left view of FIG. 1 ;

FIG. 5 is a right view of FIG. 1 ;

FIG. 6 is a top view of FIG. 1 ; and,

FIG. 7 is a bottom view of FIG. 1 .

The broken lines shown on the drawings depict portions of the mask that form no part of the claimed design. 

CLAIM The ornamental design for a mask, as shown and described. 